The London Underground will operate 24 hours a day at weekends from 2015 as part of plans for a “21st-century tube service”, it has been announced.

The company which runs the service, London Underground (LU), says it also plans to close most ticket offices and move to a system of direct, contactless bank payments to pay for journeys.

But bosses also said around 750 jobs will be cut as part of the package of changes, and those members of staff who remain will be based in halls and on platforms rather than in ticket offices - all of which could go.

While many in London will be pleased by the extended service, unions have hit out at the mayor for a series of measures which they branded 'hypocritical'.

The plans are designed to help slash Transport for London's budget by around £50 million a year, or £270 million over the term of Transport for London's business plan to 2020/21.

And the Rail Maritime and Transport union warned of industrial action, adding that staffing levels will be “decimated”.

General secretary Bob Crow said: “The mayor must believe he is some sort of magician if he thinks he can slash jobs and still run safe services when everyone knows that staffing has already been cut to the bone while passenger demand continues to rise.

We will work with sister unions and the public to fight these plans and that means using every campaigning, political and industrial tool at our disposal and our executive will be looking at a timetable and a strategy for that campaign, including a ballot for industrial action.”

Manuel Cortes, leader of the TSSA rail union, accused Mr Johnson of being the “hypocrite of the decade”, saying the announcement would lead to the closure of all 268 Tube ticket offices by the end of next year.

“It beggars belief that the mayor who was elected in 2008 on a pledge to keep open every ticket office is now planning to close every single one, with all that means for safety and jobs.”

LU said that from 2015 travellers will be able to take the Tube home at any hour of the night on Fridays and Saturdays.

Weekend services will run through the night on core parts of the system, initially the Piccadilly, Victoria, Central and Jubilee lines and parts of the Northern line.

Wi-Fi coverage is also set to be extended, and the investment of billions of pounds in modernising lines will continue, London mayor Boris Johnson and LU managing director Mike Brown said.

“LU is committed to delivering the reduction in operational staff numbers without any compulsory redundancies,” said a statement.

Mr Brown said: “People are at the heart of this vision - our customers and staff. My commitment to London is that all Tube stations will continue to be staffed and controlled in future, with more staff visible and available to help customers buy the right ticket, plan their journey and keep them safe and secure. We will continue to make the Tube more accessible and provide assistance at stations for all our customers who need it.”

Shadow London minister Sadiq Khan said: “The mayor of London has today ripped up his manifesto promise to the people of London. As a result of his plans, Londoners will feel more anxious travelling at times when stations may be deserted.

“We support looking at the way TfL staff work so that it reflects the changing needs of the modern underground system, but the mayor is using this as an excuse to cut staffing levels, which is reckless and irresponsible.”

Mr Johnson said: “For 150 years the Tube has been the beating heart of London, its tunnels and tracks providing the arteries that have transported millions of people and helped to drive the development and economic growth of our great city.

“Now it is time to take the Tube to the next level and so for the first time in London's history, we will provide a regular 24-hour Night Tube service at weekends. This will not just boost jobs and our vibrant night-time economy, it will further cement London's reputation as the best big city on the planet in which to live, work, visit and invest.”

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